This is a competing proposal for research in statistical issues related to environmental risk for carcinogenicity and teratology. The proposed problems are motivated both by toxicological studies in rodents and epidemiological studies in humans. Specific aims include: Application of local likelihood methods to three-state models for rodent carcinogenicity experiments; Developing improved approaches to quantitative risk assessment based on epidemiological data; and Developing new methods for the analysis of correlated date. Empirical data analysis will play a central role in achieving these specific aims. In addition to addressing important real world questions motivated by environmental risk assessment, the proposed research offers useful contributions to general statistical methodology in survival analysis, meta-analysis, clustered data methods, hierarchical modeling and analysis of multiple outcomes.